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1、第十三篇(2)SolarPowerwithoutSolarCellsAdramaticandsurprisingmagneticeffectoflightdiscoveredbyUniversityofMichiganresearcherscouldleadtosolarpowerwithout51semiconductor-basedsolarcells.Theresearchersfoundawaytomakeanopticalbattery,"saidStephenRand,aprofessorinthe
2、departmentsofElectricalEngineeringandComputerScience,PhysicsandAppliedPhysics・Lighthaselectricandmagnetic52,Untilnow,scientiststhoughttheeffectsofthemagneticfieldweresoweakthattheycouldbeignored.WhatRandandhiscolleaguesfoundisthatattheright53,whenlightistrav
3、elingthroughamaterialthatdoesnotconductelectricity,thelightfieldcangenerateeffectsthatare100milliontimesstrongerthanpreviouslyexpected.54thesecircumstances,themagneticeffectsdevelopstrengthequivalenttoastrongelectriceffect.“Thiscouldleadtoanewkindofsolarcell
4、withoutsemiconductorsandwithoutabsorptiontoproduce55separation,nRandsaid・“Insolarcells,thelightgoesintoamaterial,getsabsorbedandcreatesheat.Here,we56tohaveaverylowheatload・Insteadofthelightbeingabsorbed,energyisstoredinthemagneticmoment.Intensemagnetizationc
5、anbeinducedbyintenselightandthenitisultimately57ofprovidingacapacitivepowersource.nWhatmakesthispossibleisapreviouslyundetectedbrandof“opticalrectification,”saysWilliamFisher,adoctoralstudentinappliedphysics.Intraditionalopticalrectification,lighfselectricfi
6、eldcausesachargeseparation,orapulling58ofthepositiveandnegativechargesinamaterial.Thissetsupavoltage,similartothatinabattery.RandandFisherfoundundertherightcircumstancesandin59typeofmaterials,thelighfsmagneticfieldcanalsocreateopticalrectification.Thelightmu
7、stbeshonethroughamaterialthatdoesnot60electricity,suchasglass・Anditmustbefocusedtoanintensityof10millionwattspersquarecentimeter.Sunlightisn'tthisintense61itsown,butnewmaterialsarebeingsoughtthatwouldworkatlowerintensities,Fishersaid.“Inourmostrecentpaper,we
8、showthatincoherentlightlikesunlightistheoreticallyalmostas62inproducingchargeseparationaslaserlightis,”Fishersaid・Thisnewtechniquecouldmakesolarpowercheaper,theresearcherssay.Theypredictthatwith
